Bilayer electrodes

Abstract

The invention herein comprises a polymer bilayer which eliminates the spontaneous release of an active molecule by ion exchange. The spontaneous release is slowed by the application of a second polymer layer to the top of the electroactive polymer. The electroactive bilayer is preferably polypyrrole. The second polymer layer is preferably poly(vinyl butyral), poly(vinyl acetate) or nafion. This second layer stops the spontaneous release of the active molecule. The active molecule will usually be a pharmaceutical agent or drug. This bilayer allows a more effective controlled drug delivery system wherein the quantities and timing of the drugs can be given to the human being/animal patient with a high degree of certainty and predictability.

What is claimed is:  
     
         1 . A controlled drug release electrode system comprising an electroactive polymer having an ionic exchangeable releasable dopant thereon and an effective conforming thickness of a water insoluble film forming overlayer substantially impermeable to said dopant.  
     
     
         2 . The electrode system of  claim 1  wherein said effective conforming thickness is of a thickness sufficient to be substantially impermeable to said dopant.  
     
     
         3 . The system of  claim 1  wherein said insoluble film forming overlayer comprises a polymer.  
     
     
         4 . The system of  claim 3  wherein said polymer comprises poly(vinyl butyral), nation, or poly(vinyl acetate).  
     
     
         5 . The system of  claim 4  wherein the poly(vinyl acetate) is at the most 88% hydrolyzed.  
     
     
         6 . The system of  claim 4  wherein the poly(vinyl acetate) is less than or equal to 40% hydrolyzed.  
     
     
         7 . A process for preparing a controlled drug release electrode system, said system comprising an electroactive polymer having an ionic exchangeable dopant thereon and an effective conforming thickness of a water insoluble film forming overlayer substantially impermeable to said dopant thereon, said process comprising the effective application of said film forming overlayer in an adherent fashion to said polymer.  
     
     
         8 . The process of  claim 7  wherein said application process is selected from the group consisting of dipping, coating, printing, spraying and vapor deposition of said film forming overlayer to said polymer.  
     
     
         9 . The process of  claim 7  wherein said film forming overlayer is adherent to said polymer.  
     
     
         10 . The process of  claim 8  wherein said film forming overlayer comprises a polymer.  
     
     
         11 . The process of  claim 8  wherein said polymer comprises homopolymers and copolymers of polypyrrole, N-substituted pyrrole and C-substituted pyrrole.  
     
     
         12 . The process of  claim 11  wherein said polymer comprises polypyrrole.  
     
     
         13 . The process of  claim 10  wherein said polymer comprises poly(vinyl butyral), nation, or poly(vinyl acetate).  
     
     
         14 . A method for treating patients using a controlled drug release electrode system, said system comprising an electroactive polymer having an ionic exchangeable dopant thereon and an effective conforming thickness of a water insoluble film forming overlayer substantially impermeable to said dopant, said method comprising contacting said patient with said electrode system and applying an effective potential to said electrode system whereby said drug is made effectively available to the patient.  
     
     
         15 . The method of  claim 14  wherein said film forming overlayer comprises a hydrophobic polymer.  
     
     
         16 . The method of  claim 15  wherein said overlayer is selected from the group consisting of poly(vinyl butyral), poly(vinyl acetate), or Nafion.  
     
     
         17 . The method of  claim 14  wherein said electroactive polymer comprises homopolymers and copolymers of polypyrrole, N-substituted pyrrole and C-substituted pyrrole.  
     
     
         18 . The method of  claim 17  wherein said electroactive polymer is polypyrrole.  
     
     
         19 . A process of using a polymeric material as a controlled drug delivery system comprising the use of a polymer bilayer containing drug molecules to impede the spontaneous release of said drug molecules when no electrochemical stimulus is applied.  
     
     
         20 . The process of  claim 19  wherein the polymer bilayer comprises an electroactive polymer and a second polymer layer, where the second polymer layer is applied to the top of the electroactive polymer.  
     
     
         21 . The method of  claim 20  wherein the second polymer layer is made of hydrophobic material and is crosslinked.  
     
     
         22 . The method of  claim 20  wherein the second polymer layer is selected from the group consisting of poly(vinyl butyral), Nafion and poly(vinyl acetate).  
     
     
         23 . The method of  claim 20  and  22  wherein the electroactive polymer is homopolymers and copolymers of polypyrrole, N-substituted pyrrole and C-substituted pyrrole.  
     
     
         24 . The method of  claim 23  wherein said electroactive polymer is polypyrrole.  
     
     
         25 . An article of manufacture comprising a controlled drug release electrode system comprising an electroactive polymer having an ionic exchangeable dopant thereon and additionally an effective conforming thickness of a water insoluble film forming overlayer substantially impermeable to said dopant.  
     
     
         26 . The article of manufacture of  claim 25  where said article of manufacture is placed in contact with a patient's skin.  
     
     
         27 . The article of manufacture of  claim 26  wherein an effective potential is applied to said electrode wherein said potential causes the release of said drug, making said drug effectively available to the patient.  
     
     
         28 . The method of  claim 25  wherein said film forming overlay comprises a polymer made from hydrophobic material which is crosslinked.  
     
     
         29 . The method of  claim 28  wherein said electroactive polymer comprises homopolymers and copolymers of polypyrrole, N-substituted pyrrole and C-substituted pyrrole.  
     
     
         30 . The method of  claim 29  wherein said electroactive polymer comprises polypyrrole.  
     
     
         31 . A process of creating an electrochemical responsive controlled drug delivery system comprising loading a film of an electroactive polymer with an active ingredient, applying a second polymer layer to said electroactive polymer loaded with an active ingredient, and allowing said second polymer layer to dry.  
     
     
         32 . The process of  claim 31  where said electroactive polymer comprises homopolymers and copolymers of polypyrrole, N-substituted pyrrole and C-substituted pyrrole.  
     
     
         33 . The process of  claim 32  wherein said electroactive polymer comprises polypyrrole.  
     
     
         34 . The process of  claim 33  wherein said electroactive polymer is produced by depositing polypyrrole onto a stainless steel electrode by utilizing a constant potential from an aqueous solution comprising a pyrrole, a salt of an anionic or cationic active ingredient, and a dopant.  
     
     
         35 . The process of claims  31  wherein the second polymer layer is poly(vinyl butyral).  
     
     
         36 . The process of  claim 35  wherein the second polymer layer is allowed to dry at about room temperature.  
     
     
         37 . The process of claims  31  wherein the second polymer layer is nation.  
     
     
         38 . The process of  claim 37  wherein the second polymer layer is allowed to dry at about 150° C. for 1 hour.  
     
     
         39 . The process of  claim 31  wherein the second polymer layer is poly(vinyl acetate).  
     
     
         40 . The process of  claim 39  wherein the second polymer layer is allowed to dry at room temperature.  
     
     
         41 . The process of  claim 42  wherein the second polymer layer is thermally crosslinked in a vacuum for about 30 minutes at 70° C. and then for 30 minutes at 150° C.  
     
     
         42 . The process of  claim 41  wherein the poly(vinyl acetate) is less than 88% hydrolyzed.  
     
     
         43 . The process of  claim 42  wherein the poly(vinyl acetate) is about 40% hydrolyzed.  
     
     
         44 . A dopant controlled release system comprising an electroactive polymer having an ionic exchangeable releasable dopant thereon and an overlayer to lessen the spontaneous release of said dopant.  
     
     
         45 . The system of  claim 44  wherein the overlayer is made of a hydrophobic material.  
     
     
         46 . The system of  claim 45  wherein the overlayer is highly networked.  
     
     
         47 . The system of  claim 46  wherein the overlayer is highly networked due to crosslinking.  
     
     
         48 . The system of  claim 45  wherein the overlayer is chosen from the group consisting of poly(vinyl butyral), poly(vinyl acetate), and nation.  
     
     
         49 . The system of  claim 48  wherein said electroactive polymer comprises homopolymers and copolymers of polypyrrole, N-substituted pyrrole and C-substituted pyrrole.  
     
     
         50 . The system of  claim 49  wherein said electroactive polymer comprises polypyrrole.  
     
     
         51 . The method of  claim 45  wherein said dopant is a biologically active ingredient.  
     
     
         52 . The method of claim  51  wherein said biologically active ingredient is a pharmaceutical compound.  
     
     
         53 . The method of claim  52  wherein said pharmaceutical compound is selected from the group consisting of nutritional supplements, anti-inflammatory agents(e.g. NSAIDS such as s-ibuprofen, ketoprofen, fenoprofen, indomethacin, meclofentamate, mefenamic acid, naproxen, phenylbutazone, piroxicam, tolmetin, sulindac, and dimethyl sulfoxide), antipyretics, anesthetics including benzocaine, pramoxine, dibucaine, diclonine, lidocaine, mepiracaine, prilocaine, and tetracaine; demulcents; analgesics including opiate analgesics, non-opiate analgesics, non-narcotic analgesics including acetaminophen and astringent including calamine, zinc oxide, tannic acid, Hamamelis water, zinc sulfate; natural or synthetic steroids including triamcinolone, acetonide, prednisone, beclomethasone dipropionate; asthmatic drugs including terbutaline sulfate, albuterol, leukotriene receptor antagonists; electrolytes, metals and minerals; antianxiety and antidepressant agents; antimicrobial and antiviral agents; antihistamines; immune-suppression agents; cholesterol-lowering agents; cardiac and high-blood pressure agents and mixtures thereof.